The use of reactive binder for carbon-based oxygen reduction reaction catalyst in neutral medium

Abstract In this study, we report the use of reactive binding strategy to fix carbon-based oxygen reduction reaction (ORR) catalyst to metal current collector for the first time. Reactive binder, e.g. phenol-formaldehyde resin (PFR) oligomer, is developed as alternatives to the popularly used Nafion binder to bond carbon-based ORR catalyst, e.g. Pt/C (Pt loaded on VulcanX C72R carbon black), onto stainless steel (SS) current collector for use as cathode in microbial fuel cells. The ORR performance of the Pt/C electrode bonded by PFR (Pt/C-PFR) is studied in neutral medium and compare with that bonded by the Nafion binder (Pt/C-Nafion). Results show that the dosage of PFR binder in the Pt/C-PFR could be only half that of Nafion binder in the Pt/C-Nafion electrode, and the resulted Pt/C-PFR shows superior ORR electrocatalytic performance and stability to that of Pt/C-Nafion electrode on the SS current collector. A strong interaction is developed between the SS and the PFR binder, which is four times of that between the SS and the Nafion binder. X-ray photoelectron spectroscopy results reveal that the higher bonding strength can be attributed to the formation of C-O-Fe bonds between the PFR and the SS. This study offers a low-cost and effective binding strategy for generating high-performance and scalable ORR electrode.